title: The effect of sperm-oocyte incubation time on in vitro embryo development using sperm from a tetraparental chimeric bull.
abstract: The present study was designed as 5 x 4 factorial to investigate the effects of using sperm from 5 bulls, and varied sperm-oocyte incubation times (5, 10, 15 and 20 h) on the fertilization, cleavage rates and blastocyst formation on an in vitro bovine embryo production system. The bulls included a tetraparental Chimera, its sires (Japanese Black and Limousin), its maternal grand-sires (Japanese Brown and Holstein). The proportion of polyspermy, 2-pronuclei formation, fertilization, cleavage and development to blastocyst were affected (P < 0.001) by the duration of sperm-oocyte incubation, as well as by the interaction between bulls and their corresponding sperm-oocyte incubation time. Blastocyst rate observed after 5 h in oocytes inseminated with Chimera, Japanese Black and Limousin were higher (p < 0.05) than those observed at 20 h incubation. The proportion of blastocysts from oocytes inseminated with Japanese Black observed at 10 h of incubation did not differ from that of Chimera, but both were higher (p < 0.05) than those observed for the Limousin, Japanese Brown and Holstein sires. The present study showed that there was an effect by the duration of sperm-oocyte incubation on in vitro embryo development. The optimal time of sperm-oocyte incubation for the Chimera was similar to that of its sires (Japanese Black and Limousin) but differed from its maternal grand-sires (Japanese Brown and Holstein). The fertilization rates for the sperm from the Holstein bull increased up to 15 h suggesting that this might be the only bull that would benefit from a long incubation period for insemination.
authors.affiliation: United Graduate School of Vetrinary Sciences, Yamaguchi University, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Sumantri
authors.forename: A
authors.initials: A
authors.lastname: Boediono
authors.forename: M
authors.initials: M
authors.lastname: Ooe
authors.forename: M
authors.initials: M
authors.lastname: Murakami
authors.forename: S
authors.initials: S
authors.lastname: Saha
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D002678:Chimera / Q000502:physiology*; D005314:Embryonic and Fetal Development / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods* / Q000662:veterinary; D008297:Male; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology*; D013997:Time Factors